Method and apparatus for refrigeration



E. RICE. JR A 2,055,158

METHOD AND APPARATUS FOR REFRIGERATION Sept. '22, 1936.

Filed. Jul 14. 19:50 14 Sheets-Sheet 1 Sept. 22, 193 6. E. RIC E .JRL1 2,055,158

METHOD AND APPARATUS FOR REFRIGERATION I Filed July 14. 1 930 14 Sheets-Sheet 2 &

Sept. 22', 1936. E. Rice. JR 2, 5

METHOD AND APPARATUS FOR REFRIGERATION Filed July 14. 1930 14 Sheets-Sheet s Sept. 22, 1936. E. RICE, JR

METHOD AND APPARATUS FOR REFIGERATION 14 Sheets-Sheet 4 Filed July 14, 1930 Sept. 22, 1936. E. RICE, .JR 2,055,158

METHO AND APPARATUS FOR i KEFR-I'GERATION Filed July 14. 1950 14 Sheets-Sheet 5 Sept. 22, 1936. E. RICE. m 2,055,158

METHOD AND APPARATUS FOR REFRIGERATION- Filed July 14. 1930 14 Sheets-Sheet s Sept-22, 1936. E. RICE. JR I 2,055,158

I METHOD AND APPARATUS FOR REFRIGERATION Filed July 14. 1930 14 Sheets-Sheet 7 S ept.22,1936. A E. RICE, JR 1 2,055,158,

METHOD AND APPARATUS FOR REFRIGERATION Filed July 14.1930 1-4 Sheets-Sheet 8 v litugpzaa sg tr zz, 1936.

E. RICE, JR

METHOD' AND APPARATUS FOR REFRIGERATION Filed July 14. 1930 14 Sheets-Sheet 9 Mrs M Sept. 22, 1936. 5- RICE, JR 2,055,158 A METHOD AND APPARATUS FOR REFRIGERATION f Filegl July 14. 1930 14 Shee't s-Sheei'. 1b

Sep t. 22,1936. E. RICE. 1R 2,055,158

METHOD AND APPARATUS FOR REFRIGERATION Filed July 14. 1950 14 Shets-Sheer. 11

Sept. 22, 1936.

E. RICE; JR

METHOD AND APPARATUS FOR REFRIGERATION Filed July 14. '1930 14 Sheets-Sheet 12 Sept. 22, 1936. E. RICE. JR 7 5 5 METHOD AND APPARATUS FOR REFRIGERATION Filed July 14. 1950 14 Sheets-Sheet 1s Se t. 22, 1936. E. RICE. JR 7 METHOD AND APPARATUS FOR REFRIGERATION 14 Sheets-Sheet 14 Filed July 14. 1930 QIZZLOI" ifii r 5 avid 47. M

Patented Sept. 22, 1936 UNITED STATES METHOD AND APPARATUS FOR REFRIGERATION Edward Rice, Jr., Philadelphia, Pa., asslgnor to International Carbonic, Inc., Wilmington, Del, a corporation of Delaware Application July 14, 1930, Serial No. 467,999

35 Claims. (01 6H1) This application is a continuation in part of my application for patent filed June 21, 1929, Serial Number 372,754.

This invention relates to improvements in methods and means for refrigerating by use of solid refrigerants, such as water ice (solid H20), and carbon dioxide ice (solid CO2) A principal object of the invention is 'to' provide a method of refrigerating by means of solid refrigerants that shall be more efficient than the prior methods and shall permit of close regulation of the effective refrigerating temperatures.

Another object of the invention is to provide a method of refrigerating by means of solid refrigerants whereby the effective refrigerating temperatures are to a substantial degree independent of the volume of the refrigerant, and to this latter end, the invention contemplates the provision of a method for materially increasing the refrigerating efficiency of relatively small quantities of a solid refrigerant.

More specifically, an important object of the invention is the provision of a method of refrigeration by the use of a solid refrigerant which will produce effective refrigerating temperatures in the refrigerating chamber more closely approximating the melting or subliming temperature of the ice than the heretofore known methods, and which will maintain such temperatures even when the mass of ice has been reduced to relatively small dimensions.

Still another object of the invention is the provision of a method of refrigerating by use of solid refrigerants which will permit a rapid acceleration in the rate of ice meltage or sublimation irrespective of the volume of the refrigerant when the temperatures in the refrigerated area are in creased.

A still further object of the invention is to provide a method of refrigeration by means of a Solid refrigerant which will permit the refrigeration of practically any desired space whether occupied with a gas (including-air), liquid. solid or a com ductor sufliciently large to transmit the required amount of heat for maintaining a predetermined effective refrigerating temperature. I

The invention further contemplates the provision of refrigerating apparatus for use interchangeably with solid C02, solid H2O or other solid refrigerant, in which the principal heat transfer to the solid refrigerant takes place from the refrigerated area or mass to a conductor of high thermal conductivity and extended surface, thence cflnductively to a relatively small surface of the refrigerant through a section of the conductor of sufllcient size to transmit an amount of heat required for maintaining a predetermined effective refrigerating temperature and in which differences in the melting or subliming temperatures of the different refrigerants may be compensatedby means of variable conductor resistances placed between the conductor and the refrigerant.

Still more specifically, as regards the use of solid H20 and similar solid refrigerants of relatively high melting point, an object of the invention is to provide a novel method of refrigeration which will produce effective refrigerating temperatures more closely approximating the melting temperature of the ice than has heretofore been possible, and will maintain such temperatures even after the volume of the ice has been reduced to relatively small amounts.

Again specifically, and as regards the use of solid refrigerants, such as solid 00:, having a relatively low melting point or point of sublimation,

another object of the invention is to provide a method of refrigerating with such refrigerants which shall be both highly efficient and capable of close and accurate regulation of the effective refrigerating temperatures, said temperatures being maintainable even when the volume of the refrigerant has been reduced to relatively small amountsl;

A stilllffurther object is the provision of refrigerating apparatus for use with solid CO: or the like in which the effective refrigerating temperature is controllable at least in part by means of insulation set up in an established principal path of heat travel between the refrigerated area or mass and the refrigerant.

' A still further object of the invention is to provide a refrigerating apparatus for use with solid CO: or the like in which provision is made for varying the effective refrigerating temperature by means of an obstruction in the principal path, of heat travel between the refrigerated area or mass and the refrigerant and in-which said chstruction may be inserted, removed or varied either manually or thermostatically during the refrigerating operation.

A further and more specific object of the invention is the provision of a method of refrigeration by the use of carbon-dioxide "ice" or the like which will permit the automatic maintenance of an approximately constant temperature in the refrigerating chamber under varying conditions of outside atmospheric temperature, of content of refrigerating chamber, and of ice supply. v

A further object of the invention is the provision of refrigerating apparatus for use with CO2 "ice or the like in which the principal heat transfer from the refrigerating chamber and its contents to the ice takes place convectively from the chamber to a conductor of high thermal conductivity, thence conductively to the ice", and in which means may be provided for regulating the convection currents in such a manner that an approximately constant temperature may be maintained in the refrigerating chamber. I

A further object of the invention is the provision of refrigerating apparatus for use with CO2 ice or the like in which the gas resulting from sublimation of the ice is retained in essentiallygas-tight channels away from the contents of the refrigerating chamber, and in which the gas escapes directly to the outside atmosphere or through piping of high thermal conductivity placed in the top of the refrigerating chamber, thus permitting a secondary heat transfer from the refrigerating chamber and its contents to the escaping CO2 gas.

A further object of the invention is to provide a method of and apparatus for refrigerating by the use of. CO2 ice or the like whereby an initial rapid chilling of the refrigerating chamber or its contents may be had when desirable by a comparatively rapid melting or sublimation of the ice", and thereafter the required temperature maintained by a much slower sublimation of the ice" store.

A further object of the invention is to provide such a refrigerating apparatus for use with CO2 ice or the like that a regulated temperature either above or below the freezing temperature of water can be maintained in the principal refrigerating chamber, while in a second chamber the temperature is not exactly regulated, but will always be considerably below the freezing temperature of water as long as the ice" store is maintained.

A further object of the invention is the production of a refrigerating unit of such character that it may be employed either in household and stationary refrigerators or in the refrigeration of railway cars, motor truck bodies, or other transportation units.

Still another object of the invention is to provide simple and relatively inexpensive refrigerating units of a character adapted for use in household and other refrigerators employing solid H2O whereby my invention may be readily available for that class of refrigeration.

The invention further resides in certain novel and advantageous structural features and details and in specific embodiments representing various applications thereof to different classes of refrigeration, all as hereinafter set forth and illustrated in the attached drawings, in which:

Figure 1 is a diagrammatic sectional view 11- lustrating an embodiment of my invention as applied to household refrigerators and similar classes of refrigerators;

Fig. 2 is a view in perspective of a refrigerating unit adapted for application to household and similar refrigerators and constructed in accordance with my invention;

Fig. 3 is a diagrammatic sectional view illustrating the method of installing the unit illustrated in Fig. 2;

Fig. 4 is a section on the line 4-4, Fig. 1;

Fig. 5 is a section on the line 55, Fig. 3;

Fig. 6 is a diagrammatic sectional view illustrating another embodiment of my invention;

Fig. 7 is a fragmentary sectional view of the embodiment shown in Fig. 6 modified for use with solid CO2 as the refrigerant;

Fig. 8 is a section on the line 88, Fig. 6;

Fig. 9 is a fragmentary sectional view similar to that of Fig. 7 but illustrating the apparatus used with a refrigerant composed of frozen brine.

Fig. 10 is a sectional view illustrating a still further embodiment of my invention;

Fig. 11 is a sectional view illustrating the embodiment shown in Fig. 10 modified for use with solid C02;

Figs. 12, 13, 14, 15 and 16 are fragmentary.v

sectional views illustrating different types of fin construction suitable for use in the practice of my invention;

Fig. 1'7 is a diagrammatic sectional view illustrating a still further embodiment of my invention;

Fig. 18 is a section on the line l8|8, Fig. 17;

Fig. 19 is a diagrammatic sectional view illustrating another embodiment of the invention;

Fig. 20 is a diagrammatic sectional view illustrating the application of the principles of my invention to the construction of a container for frozen products such as ice cream;

Fig. 21 is a section on the line 2l2l, Fig. 20;

Fig. 22 is a diagrammatic sectional view illustrating a modification of the embodiment illustrated in Fig. 20;

Fig. 23 is a section on the line 2323, Fig. 22;

Fig. 24 is a diagrammatic vertical sectional view illustrating a liquid-cooling apparatus made in accordance with my invention;

Fig. 25 is a section on the line 25-25, Fig. 24;

Fig. 26 is a diagrammatic vertical sectional view showing a further form of liquid-cooling apparatus made in accordance with my invention;

Fig. 27 is a section on the line 2141, Fig. 26;-

Fig. 28 shows another form of refrigerator storage cabinet embodying my invention;

Fig. 29 is a section on the line 2929, Fig. 28;

Fig. 30 is a vertical sectional view showing a further form of single chamber container made in accordance with my invention;

Fig. 31 is a section on the line 3l3l, Fig. 30;

Figs. 32 and 33 are vertical sectional views illustrating my invention as embodied in relatively small refrigerator containers;

Figs. 34 and 35 are, respectively, a vertical sectional view and a section taken on the line 35-35, Fig. 34, illustrating a table or cabinet type of refrigerator made in accordance with my invention and in condition for use with solid carbon dioxide or other refrigerant of relatively low melting point;

Fig. 36 is a fragmentary vertical sectional view illustrating the same cabinet as used with solid H2O or similar refrigerant of relatively high melting point;

Fig. 37 is a section on the line 31-31, Fig. 36;

Fig. 38 is a diagrammatic vertical sectional view illustrating a desirable type of shipping container embodying my invention;

Fig. 39 is a vertical sectional view through a small type of shipping refrigerator container made in accordance with my invention;

Fig. 40 is a section on the line 40-46, Fig. 39;

Figs. 41 and 42 are, respectively, a diagrammatic vertical sectional view and a section on the line 42-42,-Fig. 41, showinga similar type of container adapted primarily for use with solid H2O;

Fig. 43 is a plan view of another form of refrigerator employing my method and apparatus;

Fig. 44 is a section on line 44-44 of Fig. 43;

Fig. 45 is a section on line 45-45 of Fig. 44;

Fig. 46 is a vertical sectional view through a modified refrigerator structure;

Fig. 47 is a section on line 41-41 of Fig. 46;

Fig 48 is a horizontal sectional view of a further modified form of the invention taken on the line 48-48 of Fig. 49;

Fig. 49 is a section on line 49-49 of Fig. 48;

Fig. 50 is a semi-diagrammatic, vertical sectional view through a refrigerator car equipped with refrigeration units constructed in accordance with my invention;

Fig. 51 is a horizontal sectional view therethrough;

Fig. 52 is a fragmentary bottom plan view of a conductor plate constructed for use in my apber;

Fig. 56 is a front elevation of a household refrigerator constructed in accordance with my invention and adapted for making water ice cubes and storage of frozen products;

-Fig. 5'1 is a horizontal sectional view on line 51-51 of Fig. 58;

Fig. 58 is a vertical sectional view on line 58-58 of Fig. 57;

Fig. 59 is a horizontal sectional view taken on line 59-59 of Fig. 60 and illustrating a modification of a structure, such as shown in Figs. 56 to 58, to produce a circular refrigerator having rotating shelves;

Fig. 60 is a section on the line 60-60 of Fig. 59;

Fig. 61 is a fragmentary vertical sectional view illustrating a modification of the invention combining a structure similar to that illustrated in Figs. 43 to 49 with a structure such as illustrated in Figs. 56 to 59;

Fig. 62 is a more or less diagrammatic vertical sectional view illustrating a type of refrigerator involving the principle of my invention adapted particularly for the cooling of milk and other beverages;

Fig. 63 is a section on the line 63-63, Fig. 62;

Fig. 64 is a vertical sectional view more or less diagrammatic illustrating a type of store show case refrigerated in accordance with my invention;

Fig. 65 is a diagrammatic vertical sectional view illustrating another cooling apparatus made in accordance with my invention;

Fig. 66 is a diagrammatic vertical sectional view illustrating apparatus for quick freezing of meat, fish and other foodstuffs also embodying myinvention;

Fig. 67 is a horizontal sectional view, and

Fig. 68 is a sectional view on the line 68-68, Fig. 6'1, illustrating more or less diagrammatically an application of my invention to the refrigeration of large truck bodies;

Fig. 69 is a horizontal sectional view, and

Fig. 70 is a vertical sectional view through a refrigerator such as shown in Fig. 69, and illustrating my invention as applied to refrigeration of relatively small truck bodies;

Fig. 71 is a diagrammatic vertical sectional view of a" well known type of railway express car illustrating the method of refrigerating in accordance with my invention;

Fig. '72 is a diagrammatic vertical sectional view of a railway car showing another method of refrigeration in accordance with my invention;

Fig. 73 illustrates diagrammatically a form of refrigerating container adapted for the cooling of special food articles, such as candy or like materials, made in accordance with my invention;

Fig. 74 is a vertical sectional view of a refrigerating unit made in accordance with my invention and of a type applicable to the refrigeration of any enclosed space;

Fig. 75 is a section on the line 15-15, Fig. 74; and

Fig. 76 is a diagrammatic horizontal sectional view illustrating the use of a unit for refrigerating the various compartments of a truck or car.

Water ice or solid H2O is more widely used than any other form of refrigerant. One of the principal drawbacks in the prior methods of usingthis refrigerant or, in fact, any solid refrigerant is that although any given mass of the refrigerant, no matter how' small, has a fixed refrigerating value; yet the smaller the mass becomes, the. slower its refrigerating action becomes also. This is due to the fact that the heat is usually either entirely or almost entirely brought to the ice convectively either by air or a liquid, and the amount of heat taken up by the refrigerant, other things being equal, depends directly on the amount of the effective surface contact between the refrigerant and the circulating fluid. Obviously as the ice melts, the surface area becomes less and the refrigerating action slower. In the construction of refrigerating apparatus, this feature, heretofore, has been given no consideration, and no effort has been made to compensate for the rapid decrease in efficiency as the refrigerant loses volume and surface area. As a result, a great deal of ice is constantly being used with very indifferent or inferior results.

One reason that the mechanical household refrigerator has progressed so rapidly is because the ordinary water ice refrigerator cannot maintain satisfactory refrigeration unless it is continually serviced and kept practically full of ice at all times. For the same reason, a large and growing field for refrigeration of foodstuffs inmotor transportation has avoided the use of water ice and other solid refrigerants. Practically the only method attempted to improve the efficiency of water ice as a refrigerant has been the use of 'salt, a method of limited application which apa metal heat conductor, such as copper, aluminum or iron, and transferred through a substantial cross section of the metal conductor directly to a surface of the body of ice with which the metal conductor is either in immediate contact or in suitable conductive relation. I have found that by this method, the ice can be melted at practically a constant rate, thus providing a constant effective refrigerating temperature practically independent of the volume of the refrigerant, and even with extremely small masses of the latter. I have found also that the refrigerant can be melted at an almost inconceivable rate when large amounts of heat are passed over the extended metal surfaces. With a sufficient cross section of the conductor metal, as small as thirty square inches of contact surface with the refrigerant will suffice to melt enough water ice to keep a good household refigerator below 50 F. even on the top shelf in the warmest weather; and after the doors have been opened as along as three minutes, this refrigerator will return to its original low temperature within twenty minutes or one-half hour. It is essential in the practice of my invention that the solid refrigerant be maintained in conductive relation with a substantial metal conductor having a suitably extended surface area in the refrigerated space.

While the invention is of great importance in conjunction with the use of water ice, it is also of great value in the use of all other solid refrigerants, such as solid carbon dioxide and frozen brine. The apparatus embodying my invention need vary only slightly to meet the requirements of the particular kind of refrigerant and the type of refrigeration required. If, for example, refrigerating temperatures around 35 to 45 F. are desired and water ice is to be used by reason of its cheapness and availability, then a relatively large amount of extended conductor or fin surface will be required because of the small temperature differential between the water ice and the temperature required; while the same temperatures can be secured by use of solidcarbon dioxide with considerably less surface area by reason of the fact that with solid carbon dioxide the conductor can be chilled to almost any temperature required down to say minus 50 F., and accordingly a relatively large temperature differential be maintained between the conductor and the refrigerated space. Obviously if temperatures are wanted near or below the melting point of water ice, then some other solid refrigerant may be used with a sufficiently low melting or subliming point that the conductor can be put at a temperature affording the differential required to maintain the refrigeration wanted.

Frozen brine may be used especially when put up in small and easily handled units in liquidtight metal containers. The heat transferred from the conductor to the solid brine through the metal container, however, is not as constant and controllable as in the direct contact of water ice with the conductor or the contact of carbon dioxide ice with the conductor through a known amount of conducting resistance, as hereinafter more specifically set forth. However, as the frozen brine can be provided with a melting point practically anywhere between 32 F. and considerably below zero and has now come into more common use and also is comparatively cheap, it is apparent that it will have a limited use as a solid refrigerant means in my method of refrigeration. Of course, frozen brine directly in solid state can be used in the same way as water ice or carbon dioxide ice by permitting the melted brine to drain off.

When using solid refrigerants such as carbon dioxide ice with a temperature considerably below the melting point of water ice, the use of predetermined known conductor resistances interposed between the conductor and the refrigerant is an important part of my method, as it affords a large degree of control over the action of the refrigerant and a quick convenient method of varying the temperature of the extended conductor surface, and thus the effective refrigerating temperature.

It will be understood that for maximum control of refrigeration, with this type of refrigerant it is desirable to limit so far as feasible transfer of heat from the refrigerated space or mass to that passing through the conductor. This can be accomplished by providing adequate insulation preventing transfer by radiation or by other than conduction through the selected conductor. By thus establishing a principal and practically sole path of transfer and utilizing in conjunction therewith suitable known resistances, a substan tially perfect control may be obtained. This method of control also affords a simple method for providing apparatus suitable for use with refrigerants such as water ice and carbon dioxide ice having widely different melting points. Thus a single refrigerating apparatus can be built that can use as a refrigerant either carbon dioxide or water ice or frozen brine, or, in fact, any solid refrigerant, and that can maintain practically any required temperature under constant outside temperature conditions within the limits of the particular refrigerant used by a simple manipulation of conductor resistance interposed between the conductor and the refrigerant, and by providing in the same apparatus either manually or thermostatically-operated means to regulate the convection currents from the extended conductor surfaces or fins, the required temperature can be maintained irrespective of normal outside temperature variations.

With reference to the drawings, in which I have illustrated various specific applications of my invention to different types and classes of refrigeration, and with particular reference to Figs. 1 and 4, the reference numeral I may indicate the outer shell or case of a household refrigerator of well known type, this refrigerator including a central vertical bafile wall 2 and a compartment 3 in one of the upper corners for reception of the refrig erant. In accordance with the prior practice, refrigeration is obtained in this type of refrigerator by the convective action of air currents circulated as indicated by the arrows downwardly over and around the ice in the compartment 3, downwardly through an aperture 4 provided in the base of this compartment, under thebaflie 2, and upwardly in the main refrigerating chamber 5, I accordance with my invention, I provide with the chamber 3 shelves 6, 6, for reception of the refrigerant, which shelves incline inwardly towards a conductor 1 provided with a plurality of projecting fins 8, as most clearly shown in Fig. 4. Inclination of the shelves 6 insures retention of the face of the ice masses 9 supported on these shelves in close contact with the conductor 1, which latter is located as shown in relation to the baflie wall 2 so as to provide between the vertically arranged fins, the conductor 1, and the effective refrigerating temperature in the refrigbaliie vertical passages through which the convective currents circulate downwardly over the extended surface of the conductor. As the ice melts, the latter feeds by gravity up against the conductor, thereby maintaining continuous contact between one face of the ice mass and the conductor. The ice meltage passes out through the usual drain H, and the air after circulating over the conductor and its fins comes in contact with this melted ice water, which removes the undesirable odors from the air, and then passes from the refrigerator. With apparatus of this type, it is possible to maintain relatively low temperatures within the casing even when the ice has been reduced to a very small volume.

In Fig. 2 I have illustrated in perspective a refrigerating unit made in accordance with my invention and of a type adapted for insertion in household refrigerators of the usual type. This unit comprises a rectangular casing l2 open at top and bottom and having in the interior a plurality of vertical fins l3. At the lower end of the forward wall is a depending apron ll which at its bottom edge turns upwardly to form a channel adapted to receive the drip of the melting ice,

and from this channel extends downwardly a drain pipe I5. The unit also comprises an inclined shelf I6 which provides for maintaining continuous contact between the refrigerant and the inner vertical wall I! of the unit. Preferably this wall I! of the unit and the fins l3 are made of copper, aluminum or other metal having a relatively high conductivity factor.

As shown in Fig. 3, this unit may be secured in an upper corner of the refrigerator case l8, it being noted that the forward wall IQ of the unit terminates at the top at a point below the upper end of the fins l3, whereas the rear wall H extends to the top of the fins which, in the present instance, abut the upper or top wall of the casing. In this manner, a circulation of the convective air currents is set up downwardly through the unit between the fins l3 and over the face of the rear conductor wall 11. The meltage passes through apertures at the inner or lower end of the shelf l6 and falls downwardly into the channel apron l4 whereby the air currents after passing over the surfaces of the conductor pass through the dripping water, which latter acts to remove the refrigerator odors'from the air. In orderto prevent excessive condensation of moisture and possible dripping of this moisture from the shelf IS on the stored food, the latter preferably is provided with a layer of suitable insulating material 2|.

It will be noted that each of the devices described above meets the essential requirements of my invention. In each instance, a conductor is provided for conducting heat from the space to be refrigerated to the refrigerant. This conductor is so formed, with fins in the present in stance, as to present to the space to be refrigerated a relatively extended area, and its cross sectional dimensions are entirely adequate to transmit heat in required amount picked up on the said extended surfaces to the surface or surfaces of the ice with which the conductor is in direct contact. Since in the use of water ice this direct conductive contact between the conductor and the ice is essential, provision is made in the form of the inclined ice-supporting shelves to maintain the refrigerant in constant contact with the conductor. With this arrangement, the heat may be carried to the refrigerant at a rate insuring maintenance of a predetermined adequate erated space even when the ice has been reduced to an extremely small volume. With this device, therefore, it is possible to maintain adequate refrigerating temperatures with relatively infrequent servicings, the refrigerant being adequate even after the volume is greatly reduced from the maximum capacityof the refrigerator.

In Figs. 6 to 9, inclusive, I have illustrated application of the invention to a refrigerator of the overhead icing" type. In this instance, the casing 25 has in its interior and upper portion a refrigerant-supporting shelf 26 which inclines from opposite sides towards the center whereby a solid refrigerant placed thereon has a tendency to gravitate toward the center. From the depressed mid section a drain pipe 21 extends downwardly and runs to the exterior of the casing. Projecting from the under side of the shelf and towards its outer edge and extending in a continuous series completely around the four sides of the shelf, as illustrated in Fig. 8, is a plurality of fins 28, and beneath these fins is a continuous baffle plate 29. Convective circulation of the air within the casing is set up as indicated by the arrows, the air passing between the fins and in tzzgntact with the surface of the conductor shelf In Fig. 7, the same construction is shown as modified for use with solid carbon dioxide. In this instance, conductor resistance in the form of sheets 3| of heat-insulating character is interposed between theice and the conductor shelf 26. Also the solid carbon dioxide is completely surrounded by insulation 32. The refrigerant is in conductive relation with the conductor 26 through the resistance 3|, which is of predetermined value and selected to maintain a predetermined effective refrigerating temperature. Gases of sublimation may escape through the pipe 21. It will be noted both as regards the use of water ice and dry refrigerant, a conductive relation between the refrigerant and-the conductor 26 is maintained. In Fig. 9, I have illustrated the same apparatus used with frozen brine containers. 33. These containers with the brine in the solid state are supported upon the shelf 26, suitable conductor resistance 3| being inserted between the conductor 26 and the said containers, and the latter also being surrounded by suitable insulation 32. In this instance, the drain pipe from the shelf 26 is eliminated. In Fig. 10, I have illustrated a form of fin con ductor suitable for use in the practice of my invention and made of a heavy copper conductor plate 35 bent at right angles, to which are soldered or welded thin copper fins 36 on both the vertical and horizontal walls. At the junction of these two walls an outlet pipe 31 is provided for elimination of the ice meltage. This type of refrigcrating, unit is adapted for, use in refrigerators with water ice where it is desirable to maintain The lower wall of the unit in assembly is inclined towards the vertical wall so that the ice tends to. maintain a position in the angle with adjoining faces in contact with the vertical and bottom walls respectively.

Fig. 11 shows a type of conductor of primary value in connection with carbon dioxide ice. This unit comprises an angular casting 38 of aluminum with copper fins 39. The ice-supporting wall is slightly inclined towards the juncture with the upright wall, and in the angle outlets 4| are provided for elimination of the gases of sublimation. The principal heat transfer in this instance takes place through the thin copper fins, down the upright side of the casting to the bottom or icesupporting wall. Interposed between the solid carbon dioxide and this lower wall is a suitably selected conductor resistance 42, and the ice is also surrounded by suitable insulation 43.

In Figs. 12 to 16, inclusive, I have illustrated various types of fin conductors which have been found suitable in the practice of my invention. The form of conductor illustrated in Fig. 12 is one that can be conveniently used for household refrigeration purposes, this being made up from a number of bent copper sheets 45 soldered together at the points designated 46 so as to present a substantially fiat conductor plate surface for contact with the solid refrigerant and a considerably extended fin surface for contact with the convection currents.

Fig. 13 shows a similar construction in which the outer ends 41 of the projecting fin portions are turned inwardly toward each other so as to afford the same amount of contact surface in a In Fig. 17, I have illustrated my invention as applied to a water cooler employing solid carbon dioxide as the refrigerating medium.- In this instance, the conductor forming an essential part of the device consists of a solid aluminum or copper receptacle 55'which is embedded in solid insulation 56. A chamber 51 is provided in the insulation 56 for the water or other liquid to be cooled. This chamber, as shown in Fig. 18, extends completely around the sides of the receptacle 55, but is spaced a sufiicient distance from the said conductor to maintain a desired tem-.

perature of the liquid for any predetermined temperature of the conductor. This temperature in turn is controlled by the thickness of conductor resistance 58 interposed between the solid carbon dioxide ice and the bottom wall of the conductor. With an arrangement of this character, I have found' it possible to maintain substantially any desired temperature of the liquid within the container 51 by simple variation in the thickness of the conductor resistance 58 which modifies the conductive relation between the conductor 55 and the refrigerant. It will be noted that in this instance the conductor while having the necessary extended surface is not provided with fins, and

that further the surfaces of the conductor arenot in direct contact with the liquid to be cooled, but are in conductive relation therewith through the insulation separating the walls of the liquid container from the said conductor.

Fig. 19 shows a similarly constructed water cooler with the addition of a storage space 60 located below the bottom of the conductor, it be-- ing possible to maintain this space at practically any required temperature by variation in the thickness of the insulating member 10 which constitutes conductor resistance between the space and the bottom of the conductor 55.

A more or less similar form of conductor is shown in Figs. 20 and 21, which show a cabinet suitable for use with solid carbon dioxide for storing ice cream, frozen foods or the like. In this instance, the conductor consists of a solid aluminum casting 62, this casting comprising a base 63 and four cylindrical vertical containers 64. In this instance, the walls of the portions 64 constitute the necessary extended surface area, provision being made for supporting the refrigerant upon the base between the said portions 64, as shown in Fig. 21. For this purpose, the refrigerant may be supported within a vertical metallic or other container open at the bottom to permit the ice to come into conductive relation with the base portion 63 of the conductor, from which it may be separated by a suitable conductor resistance member 65 selected to afford a desired temperature within the receptacle 64 in which the refrigerated material is stored. The entire conductor casting is surrounded by a suitable insulating casing 66, and provision is made in the form of removable cover plates 61 for aifording access to the interior of the container 64.

In Figs. 22 and 23, I have illustrated a similar type of refrigerating apparatus which in addition includes storage chambers or receptacles 61 embedded in the insulating casing 66 in suitably spaced relation to the sides of the container 64, these compartments 61 being readily kept at a non-freezing temperature and being suitable for holding water or other substances or materials at a relatively low but non-freezing temperature.

Figs. 24 and 25 illustrate a desirable form of water cooler adapted for use with water ice. The refrigerator comprises a copper tank H, one side of which forms an abutment for the refrigerant which is maintained in contact therewith by gravity through the medium of an inclined support 12. From this refrigerantabutted wall fins 13 project into the interior of the tank, which as illustrated has an inlet pipe 14 preferably emptying directly above the said fins. The arrows indicate the direction of the convection currents set up within the tank which carries the contained liquid over the surfaces of the fin conductor wall. This is a very efiicient form of liquid cooler in which the temperature of the liquid is reduced very rapidly, and by extending the insulating casing 15 rearwardly, the latter can be given any capacity required for the solid refrigerant to maintain the refrigerating action over very extended periods of time. As the ice melts, it will be understood that it feeds continuously by gravity towards and against the conductor plate of the tank H.

In Figs. 26 and 2'7, I have illustrated another form of liquid cooler in which a small copper tank I6 is placed at the lower end of an insulating casing 11, the upper end of the tank 16 being conical in form and being provided internally with fins 18, these upper conical walls thereby constituting the conductor forming an essential part of apparatus made in accordance with my invention. Water is fed to thetank 16 through the apex end of the conical top portion, and cracked ice or other refrigerant surrounds the intake tube 19 and is maintained by gravity in contact with the surfaces of the conical upper portion of the tank. Ice meltage is withdrawn 

